Display units including a liquid crystal display (LCD), organic light emitting diodes (OLED), a plasma display panel (PDP), an electrophoretic display (EPD), and the like are manufactured through multiple processes. Among the manufacturing processes, in particular, a process of attaching an optical film onto a panel is provided. The optical film is attached onto one plane and the other plane of the panel, and when an absorption axis of the optical film attached onto one plane of the panel and the absorption axis of the optical film attached onto the other of the panel are vertical to each other, the panel normally operates. An optical film attaching system is required, which attaches the optical films having the vertical absorption axes on both planes of the panel by one process.
In the related art, an operation of the optical film attaching system is described below, which attaches the optical films having the vertical absorption axes on both planes of the panel by one process.
FIG. 1 is a top view of an optical film attaching system of a panel in the related art.
Referring to FIG. 1, in the optical film attaching system of the panel in the related art, when a roller R1 feeding an optical film F1 having a width corresponding to a short edge of a panel W feeds the optical film F1, an attachment unit 18 attaches the optical film F1 fed by the roller R1 onto one plane of the panel W while the panel W moves toward the short edge along feeding units 12, 14, and 16. Thereafter, a pivot unit 20 pivots the panel W at 90° in a horizontal direction and an inversion unit 21 inverts the panel W at 180° in a vertical direction. In addition, when a roller R2 feeding an optical film F2 having a width corresponding to a long edge of the panel W feeds the optical film F2, an attachment unit 28 attaches the optical film F2 fed by the roller R2 onto the other plane of the panel W while the panel W is pivoted and inverted to move toward the long edge. Thereafter, the panel W is fed by feeding units 22, 24, and 26. A panel substrate polarization film attaching system in the related art, which attaches polarization films onto both planes of the panel has the following problem.
When the size of the panel increases (for example, the size of a screen is 98 inches and hereinafter, referred to as a large-area panel), in the case where the optical film having the width corresponding to the long edge of the panel is fed through the roller, a phenomenon occurs, in which the roller droops down as the width of the roller increases. As a result, when the optical film is attached onto the panel, a failure factor occurs between the optical film and an attachment planes of the panel, and as a result, the quality of the display unit deteriorates.
Since the optical film attaching system of the panel in the related art uses the optical film having the absorption axis parallel to the longitudinal direction of the optical film, the problem occurs. Accordingly, when the optical film is used, which has the width corresponding to the short edge of the panel and has the absorption axis orthogonal to the longitudinal direction of the optical film, the problem may be resolved.